## Heisenberg Indeterminacy Post Assessment #18

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Julia Lindner 1I
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Joined: Fri Sep 28, 2018 12:17 am

### Heisenberg Indeterminacy Post Assessment #18

"The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1 % of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle.

What does it mean that you know the position to an accuracy of 1%? I assumed that meant you multiply .01 by 0.05 nm, which gives you the delta x. But I tried using that value to obtain the uncertainty in speed and I didn't get one of the listed answers. Anyone know what I'm doing wrong? Could it be just a calculation error?

Chem_Mod
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### Re: Heisenberg Indeterminacy Post Assessment #18

You are correct in assuming that the uncertainty will be 0.01 x 0.05 nm- be sure to work through the calculations carefully since I believe that you may have made a calculation error. Have you taken into account the mass of an electron?